When a conventional filtering device for an aquarium is designed to be suspended inside the aquarium, it cannot be suspended outside the aquarium. Or when a conventional filtering device for an aquarium is designed to be suspended outside the aquarium, it cannot be suspended inside the aquarium. Thus, the filtering device is limited in use.
In addition, a conventional filtering device is configured in accordance with a desired function with the structure thereof being fit to a specific condition. However, the filtering device may not be applied at another condition. For example, a bubble remove device for seawater breeding and a sponge filtering device for freshwater breeding are not replaceable with each other. That's, when a person wants to change freshwater breeding to seawater breeding, the formerly used sponge filtering device cannot be used in the seawater breeding and so a new bubble remove device is required. Therefore, it is important to make the bubble remove device and the sponge filtering device replaceable for reducing breeding cost.
In addition, a conventional filtering device has not functions of heating and sterilizing breeding water in the aquarium. Additional heating or sterilizing apparatus is required to suspend at the aquarium for heating or sterilizing the breeding water in the aquarium, which causes the aquarium in disarray. Furthermore, the static suspension manner results in limited heating and sterilizing effects. Thus, it is also important to improve heating and sterilizing effects on breeding water and avoid the heating or sterilizing apparatus from adversely affecting aesthetic feeling of the aquarium.